Type I diabetics undergoing pancreatic transplantation surgery are studied pre and immediately post surgery. Longterm follow up includes these assessments: (1) study of the impact of physiologic regulation of glucose insulin kinetics and metabolic control, (2) study to provide data on endocrine markers to identify early rejection of the transplanted pancreas, (3) a study of the endocrine responses to various stimulatory tests on denervated, systematically drained, pancreas preparation.